1. Field of the Invention
The present invention relates to a golf club shaft and a golf club using the same to improve flight distance of hit ball.
2. Description of the Related Art
In recent years, to hold fair golf competitions, significant progress of flight distance of hit ball is restrained on the golf rule by controlling spring effect of a golf club head, a length of a golf club or moment of inertia of a golf club head. In such a circumstance, to improve flight distance of hit ball, JP2004-201911A1 proposed a golf club with a shaft as long as possible in a range of the rule, for example. Such golf club provides golfers with high head speeds using the longest club shaft.
However, such golf club with a long shaft tends to hit a ball at the outside the sweet spot of the club face due to the difficulty of control of the club head. Namely, smash-factor which is a ratio of a hit ball velocity to a club head velocity may decrease. Accordingly, it was difficult to improve flight distance of hit ball using the conventional golf club.
To solve the problem above, a golf club which has a club head with a weight greater than conventional club head and a club shaft with a short length is proposed. Such golf club makes the smash-factor improve, and a released ball velocity from the club face of the golf club can be faster. However, since the golf club tends to have a large moment of inertia, it is difficult to swing the golf club, and thereby the swing feeling tends to deteriorated.
It is an object of the present invention to provide a golf club shaft and a golf club using the same to improve flight distance of hit ball while keeping a better feeling of a golf swing.